Narrated Ibn 'Abbas:
"Once a delegation of 'Abdul Qais came to Allah's Apostle and said, "We belong to such and such branch of the tribe of Rab'a and we can only come to you in the sacred months. Order us to do something good so that we may (carry out) take it from you and also invite to it our people whom we have left behind (at home)." The Prophet said, " I order you to do four things and forbid you from four things. (The first four are as follows):1. To believe in Allah. (And then he: explained it to them i.e.) to testify that none has the right to be worshipped but Allah and (Muhammad) am Allah's Apostle
2. To offer prayers perfectly (at the stated times):
3. To pay Zakat (obligatory charity)
4. To give me Khumus
(The other four things which are forbidden are as follows):
1. Dubba
2. Hantam
3. Muqaiyat
4. Naqir (all these are utensils used for the preparation of alcoholic drinks)."